"Cell division is one of the most fundamental aspects of biology, the process that makes life," says Iain Cheeseman, PhD. "And it has an intrinsic beauty."
Captivated by this process while a graduate student in biology, Cheeseman began focusing on the kinetochore, a key structure that helps to divvy up DNA molecules shortly before cells divide, ensuring that each daughter cell receives a proper set of chromosomes and the genetic material they contain. He will continue advancing this research as a Whitehead Member, arriving at the Institute this fall.
Early during cell division, each chromosome is duplicated and split into two identical copies known as chromatids, which must be sorted and organized to ensure that new cells receive a single copy of each chromosome. Enter the kinetochore - a plate-like network of proteins that forms at a single site on each chromatid. Attaching the chromatid to a web of microtubules known as the spindle, the kinetochore ensures that chromatids are positioned and split correctly as the spindle pulls them apart.
"Iain will arrive here as one of the world's acknowledged leaders in the study of the kinetochore - a jumping-off point for a wide variety of biological research," says Whitehead Director David C. Page, MD. "He will be a terrific addition to the Institute."
The kinetochore is found in all organisms with a nucleus - including yeast, worms, fruit flies and humans - and works in a similar way in each. "The kinetochore is an amazing molecular machine composed of more than 60 different proteins," Cheeseman explains. "The cell has to monitor and control its activities to coordinate with the cell division process."
Working in yeast, the C. elegans worm and human cells, Cheeseman has helped to identify dozens of the kinetochore's molecular components and their specific roles. He also has started to define how the attachments between kinetochores and spindle microtubules are regulated throughout cell division. At Whitehead, he will tackle these challenges in human cells with a broad array of biochemical and cell biological research techniques, including some that he has helped to develop.
Because many cancers may be driven by errors in chromosome segregation, it is hoped that Cheeseman's studies will provide payoffs in cancer research. Certain cancer drugs target the connection between chromosomes and spindle microtubules, and some of the major proteins in the kinetochore complex have been implicated in leukemia and other diseases.